第四章课后练习题

4.1

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#GuessANumMore.py
target = 425
guess = 0
n = 0
while guess != target:
    guess = eval(input("请输入一个猜测的整数(1至1000)："))
    n += 1
    if guess != target:
        if guess > target:
            print("猜大了")
        else:
            print("猜小了")
        print("猜测的次数为：{}".format(n))
    else:
        print("猜对了")
        print("猜测的次数为：{}".format(n))

4.2

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s = input()
letters = 0
digits = 0
spaces = 0
others = 0

for c in s:
    if c.isalpha():
        letters += 1
    elif c.isdigit():
        digits += 1
    elif c == ' ':
        spaces += 1
    else:
        others += 1

print(f"英文字符：{letters}")
print(f"数字：{digits}")
print(f"空格：{spaces}")
print(f"其他字符：{others}")

4.3

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def gcm(a,b):
    while b:
        a = b
        b = a % b
    return a

def lcm(a,b):
    return (a*b)//gcm(a,b)

a = int(input())
b = int(input())
print("{}与{}的最大公约数为{}".format(a,b,gcm(a,b)))
print("{}与{}的最小公倍数为{}".format(a,b,lcm(a,b)))

4.4

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from random import randint
target = randint(1,1000)
guess = 0
while guess != target:
    guess = eval(input("猜一个整数(1~1000)："))
    if guess > target:
        print("大了!")
    elif guess < target:
        print("小了!")
    else:
        print("恭喜你猜对了!")

4.5

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import random as r
target = r.randint(1,1000)
guess = 0
times=0
while guess !=target:
    try:
        guess=int(input('请输入一个猜测的整数（1至1000）：'))
        if guess > target:
            print("猜大了")
            times+=1
        elif guess < target:
            print("猜小了")
            times+=1
        else:
            print("猜对了")
            times+=1
    except ValueError:
        print("输入内容必须为整数！")
print("一共猜了{}次.".format(times))

4.6

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year = int(input("请输入年份："))

if (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0):
print(f"{year}年是闰年")
else:
print(f"{year}年不是闰年")

4.7

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while True:
    try:
        num = int(input("请输入一个全数字的十进制整数："))
        break
    except ValueError:
        print("输入不正确，请重新输入。")

4.8

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num  = input("请输入一个带有小数点的浮点数：")
def is_float(num):
    if '.' in num:
        return True
    else:
        return False

while True:

        if not is_float(num):
            num = input("输入有误，请重新输入一个带有小数点的浮点数：")
        else:
            try:
                num == float(num)
                print("浮点数为：", num)
                break
            except ValueError:
                 num = input("输入有误，请重新输入一个带有小数点的浮点数：")